1. Field of the Invention
This invention relates to modulation of lasers for use in communications and in particular the use of coherent stark effects to achieve modulation of a laser beam.
2. Prior Art
It has been known that space applications of laser communications will ultimately depend on development of systems with low power consumption and gigahertz modulation bandwidths. The CO.sub.2 laser is an ideal source in terms of efficiency and power output, however, conventional 10 .mu.m electro-optic modulators require excessive drive voltage and power. In the past it has been demonstrated that the incoherent molecular Stark effect can provide efficient low voltage pulse modulation at several discrete CO.sub.2 laser wavelengths. Conventional incoherent Stark modulation has a bandwidth limitation imposed by the Doppler width (delta nu that is approximately 80 MHz at 10 .mu.m. Therefore there is trade-off of modulation depth for response speed at modulation rates above this frequency.
Coherent Stark switching in the Infrared (IR) has been conducted in the area of 0.1-100 .mu.s time for precise stucy of slow collision processes.